<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .address--cityList__mask{
            position: fixed;
            left: 0;
            top: 0;
            right: 0;
            bottom: 0;
            z-index: 999;
             background-color: rgba(0,0,0,.3);
        }

        #scroll__container{
        width: 100vw;
            height: 50vh;
            overflow: hidden;
            position: fixed;
            left: 0;
            bottom: -15vw;

        }


    </style>
</head>
<body>
<div class="address--selector__mask">
    <div class="scroll__container">
        <ul class="address--cityList">
            <li class="address--cityList__item"></li>
        </ul>
    </div>
</div>
</body>
<script>
    var btn = document.getElementsByTagName('button')[0];
    var  test = document.querySelector()
    var str = '';
    for (var prop in data){
        var item = document.createElement('li');
        item.className = 'address--cityList__item';
        item.innerText = prop;
        item.onclick = function(){
            cityListContainer.innerHTML = '';   //清空再次循环
            for (var prop) 
        }
        
       var warp = document.getElementById('scroll__container');
       var scroll = new BScrcoll(warp,{}); 
        
</script>
</html>